退化沙质草地植被与土壤分布特征及相关分析

Analysis on the Distribution and Correlation of the Vegetation Characteristics and Soil Properties over the Degenerated Sandy Grasslands

对科尔沁退化沙质草地的植被与土壤的分布特征及两者的相关性进行了研究。结果表明 ,退化沙质草地土壤养分含量贫瘠 ,土壤性质已经高度异质化 ;植被盖度低 ,物种较为贫乏 ;植被与其着生的土壤基质之间关系密切 ,是一个相互作用 ,相互影响的统一系统。要恢复退化生态系统 ,首先要恢复退化草地的植被 ,通过植被—土壤相互作用 ,土壤肥力可得到提高。

The study area (42°14′～43°32′N, 120°19′～121°35′E) is located in the hinterland of Horqin Sandland at the eastern part of the farming-pasture ecotone, where Naiman Station of Desertification Research, Chinese Academy of Sciences, is located in. The elevation here varies in a range of 340～360 m a.s.l. It belongs to the continental semi-arid climate, the annual air temperature is 6.4 ℃, and the annual precipitation and evaporation are 364.6 mm and 1 972.8 mm respectively. The landforms are characterized by gently rising-falling fixed, semi-fixed and mobile dunes as well as the vast sandy meadows. The loose aeolian sand soil is dominant, the content of organic matter in soils is low, and the water and fertility conservation capability is poor. The vegetation in the study area is composed of second psammophytes. In this paper, the distribution and correlation of the vegetation characteristics and soil properties over the degenerated sandy grasslands in Horqin Sandland are researched. The results show that the content of soil nutrients over the degenerated sandy grasslands is low, and soil properties have become highly heterogeneous; the vegetation coverage is low, and the plant species are less; the growth of plants is closely related to the soil matrix, and the vegetation and soils are a unitive system affecting each other. It is revealed that to regenerate the ecosystems is to firstly regenerate the vegetation of the grasslands, and the soil fertility can be raised by the vegetation-soil interaction.